Duplicolor Car Touch Up Paint might be your best bet, but the trick will be trying to color match your bike paint color to the nearest OEM manufacturer color available by DupliColor. Link:
https://www.duplicolor.com/product/...tch-automotive-touch-up-paint/#FixYourScratch
National chain stores like Autozone carries this stuff and may have a suitable match in stock, otherwise, you'd have to color match to the best of your ability then special order the paint at your Autozone.
Bike companies are not much help from personal experience. I bought an aluminum fork to replace the carbon fork on my Specialized Fatboy. The aluminum fork was to be fitted with a front rack, which explains my need to use that fork and not the CF one that my bike came with......
Painted the fork with 2 part black paint, topped with a 2 part clear coat. I wanted to install the same yellow decals my CF fork came with onto this aluminum fork, so I wrote Specialized, wanting to buy these decals. They wrote back saying that they did not stock them, nor were they available (this only after 1 year of being out of production in that yellow decal!) So, the fork remained gloss black with a top clear coat, no decals......